Zeitaku na Mi no Ue Tokimeki wa Umi wo Koete!

Karen, a young girl who entered the harem, attracted by the prospect of a life with three meals a day and a nap included, ends up taking a liking to the emperor, Tenrin, through a series of unexpected events. Karen pursues her hobbies while dodging Tenrin's advances, but while strolling around town with Tenrin, she ends up helping a foreign student, Makana, who has been caught up in some trouble. Apparently, he is being chased by police because he has a blueprint of the harem that he has no recollection of possessing. Karen tries to uncover the truth using her natural imagination, but...!?

(Source: Shueisha, translated)